This invention relates to the material handling art, and more particularly to an automatically-controlled radial scraper for moving accumulated loose or particulate material, such as aggregate, onto a radial or star feeder for subsequent distribution thereby.
The particulate material is usually delivered to the star feeder in trucks and dumped into bins or boxes which surround and fan out from the star feeder in a star-shaped pattern. The scraper is mounted on the star feeder and is utilized to convey the dumped material from the periphery of the pile thereof radially inwardly adjacent the base of the feeder. The scraper must be swingably mounted such that it may be positioned over selected boxes of the loose material for operation therein. The star feeder is usually provided with inlet valves so that, the particulate material, piled up adjacent the base thereof, may be admitted into the interior of the feeder.
Specifically, therefore, the invention concerns an automatically-controlled scraper for moving accumulated loose material onto a radial or star feeder provided with a platform, arranged on a supporting construction, the scraper including an arm for a guide roller of a hoisting cable line, one end of which is connected to a scraper bucket, and the otherend of which is connected to a lifting winch which is arranged on the platform together with a digging winch having a digging cable line connected to the other end of the scraper bucket, and a motor to drive both winches with automatically-controlled power-controlled means to couple the winches to the motor and to actuate the winch brakes.
In the case of prior art scrapers of this type, it cannot be avoided that the automatic control of the power-controlled means will, at times, fail. The prior art automatically-controlled scrapers can thus not be used in such cases without great risk, because under certain circumstances the feed of the aggregate or loose particulate material moved by the scraper cannot be interrupted. If, for example, a load-bearing concrete object is being reinforced with concrete, then the feed of the aggregate which is conveyed by the scraper into the star feeder may not be interrupted, since otherwise the concrete object does not receive the required load-carrying capacity.
For this reason, in cases where reliability of operation of the scraper is mandatory, scrapers are used in which the clutches and brakes can be actuated manually, directly by operating personnel. Experience has shown that such scrapers have very high reliability. However, scrapers of this type have the disadvantage that the person who is operating the scraper is completely occupied with it.